The Rev. Sean Connor’s eyes burned with tears as he stared at the small sign temporarily marking the grave of his close friend, Brian Smith, a 45-year-old priest who died of colon cancer weeks after diagnosis. It had a picture of the young cleric and an inscription echoing his favorite catchphrase: “Isn’t God so good?”

Connor buried him in June, in the pouring rain. Two days later, he said the memorial Mass for Martin Richard, a parishioner and the youngest victim of the Marathon bombings, on what would have been the boy’s ninth birthday. The 47-year-old priest had spent much of the spring shuttling between hospitals, caring for Martin’s devastated family and for his own dying friend.

“How come he gets to go home early?” he quipped about his departed colleague to another priest friend who had accompanied him to the cemetery, as they wept.

Connor had been a police officer like his father and his older brother, Jamie, a state trooper. He was 29 when, kneeling on the floor of an empty chapel during a Catholic retreat, he heard God call him to the priesthood. In time, he sheepishly confessed his new vocation to his co-workers and broke the news to his girlfriend.

A few years ago, he officiated at a wedding on the Cape. The groom’s uncle, a policeman, had known Connor’s father. At the reception, over drinks and a smoke, he pulled Connor aside.

“You know,” he told the priest, “you weren’t that good of a cop.”

“Thanks!”

“You tried really hard . . . But it’s not what you were meant to be.”

Yet Connor’s time in uniform shaped his ministry. The clergy sexual abuse crisis shook the church shortly after his ordination; he spent six years running abuse investigations for the archdiocese and ensuring the church was in compliance with new regulations. In 2008, he became pastor of St. Ann Parish in Neponset, a section of Dorchester that is home to many of Boston’s first responders.

And for nearly a decade he has served as a Boston Police Department chaplain, tending to officers and their families beset by suicide, illness, and accidents. “A lot of times you get the tough-guy, ‘No, I’m all right, I’m all right,’ but we can lean in and whisper, ‘He’s one of us,’ ” said Officer Jack McCarthy, who works with Connor in the Family Assistance Unit.

Still, nothing quite prepared him for Marathon Day, or the days that followed.

Consoling the Richards

Connor and his brother had spent the morning cleaning out their childhood home in Marshfield; their mother had just moved to a nursing home in Weymouth. He was sweating, unshaven, wearing jeans and a T-shirt when his pager went off, summoning him to police headquarters. He made it to downtown Boston in 20 minutes.

BILL GREENE/GLOBE STAFF

“You have all of these frantic parents clinging to their children, some of them not knowing what was wrong yet, people that were bloodied, bandaged, startled. Besides what afflicted them — they saw . . . the innocence is taken away.” — The Rev. Sean Connor, speaking about the aftermath of the Marathon bombings.

Connor and McCarthy met up at Massachusetts General Hospital, where they helped an officer with minor injuries get home. They drove by Copley Square, an experience Connor won’t recount. He called his brother later and told him, “It was like I was a wartime chaplain.”

At first, there was no cell service, then his phone would not stop ringing: Bill and Denise Richard and their three children, active members of St. Ann and pillars of the community in Dorchester, had suffered unimaginably. Little Martin was dead, and his mother and sister were badly injured.

Connor visited Denise Richard’s extended family at Beth Israel Deaconess Medical Center, then made his way to Boston Children’s Hospital, where Jane was in surgery, to find Bill.

The triage center was packed, but sounds seemed strangely muffled. Time seemed to slow.

“You have all of these frantic parents clinging to their children, some of them not knowing what was wrong yet, people that were bloodied, bandaged, startled,” Connor recalled. “Besides what afflicted them — they saw . . . the innocence is taken away.”

Fiercely protective of the Richard family’s privacy, Connor will say little about his work with them. But Bill Richard, in an e-mail, said that in the blur of that day, he remembers being surprised but relieved to see Connor walking toward him.

“There were no words, just a hug,” he said. “I think he was at a loss for words, which isn’t him. For the first few days, nobody knew what to say — everything was so horrific.

“But like others who have been there for us, he was simply present — and just being there meant everything to us.”

McCarthy, who was there, vividly recalls that moment.

“You could see the comfort come to Bill Richard,” he said. “He needed to see Sean. There were homicide detectives who were there, so deeply moved by what the family was facing, they were moved to tears, just standing there. And Sean reached out and said a little prayer with them.”

Connor
called one of the police supervisors at the blast site to assure the Richard family that a Boston police captain would stand beside their son’s body until it could be removed by the medical examiner’s office early the next morning.

Late that night, Connor drove Larry Marchese, one of Bill Richard’s best friends, back to where he had left his car. Marchese, who would become the Richard family spokesman, said Connor offered two invaluable pieces of advice: Keep saying Martin’s name. And do not, in the rush to help, make decisions for the family.

Connor became one of the small circle of close friends and relatives who devoted themselves to helping the Richards in the weeks that followed. He helped make arrangements for Martin’s funeral, ensuring the small group of mourners had total privacy. Connor knew which florist, which bus company, which funeral home could be depended upon to be discreet, Marchese said.

He became the group’s conscience and ethical guide. When someone put up a website advertising T-shirts for sale bearing Martin’s photograph, for example, he helped the frustrated and sleep-deprived Marchese see that the intention was a good one. Marchese reached out to the overeager fund-raiser and politely asked that Martin’s face and words not be used.

And Connor stayed by the family’s side, day in and day out. “I have never asked him why this has all happened to us,” Richard said in the e-mail, “maybe because in my heart, I know he doesn’t know the answer. But we have relied on him more to comfort us, our family, and friends. To be there to talk, or maybe just listen.”

Divided between hospitals

At night, Connor would go back to the rectory in Dorchester, heat up dinner in the microwave, and run upstairs to the third floor, where another tragedy was unfolding. The Rev. Brian Smith, the parochial vicar of St. Mary’s Church in Foxborough, had been diagnosed in March with colon cancer. Doctors thought it would be easily treated. After his surgery, which came shortly before the bombings, Connor invited him to stay at St. Ann to recuperate.

Smith was Connor’s first friend at seminary. A brilliant listener, he loved music and poetry and had a boyish innocence. He played straight man to Connor’s wise guy. When they were assigned to minister to inmates at the women’s prison in Framingham, Smith quaked in his boat shoes as Connor spirited contraband flowers for the chapel through security in his jacket — and presented them, with a grand flourish, to the sternest guard.

Smith would often be awake when Connor came home from the hospital. Connor would bring him warm ginger ale, clear his plates, and, sometimes, pour out the grief in his heart.

Instead of recovering, Smith lost weight, and his skin grew sallow. He went back to the hospital. The cancer was everywhere.

As April turned into May, Connor shuttled between hospitals, sometimes chatting, sometimes praying, sometimes just playing Angry Birds on his phone while Smith slept. And sometimes he kidded around.

“Looks like I picked the wrong week to quit smoking!” he would declare, quoting Lloyd Bridges’s character in “Airplane,” a movie he and Smith had loved to watch in seminary. “Looks like I picked the wrong week to quit drinking! Looks like I picked the wrong week to quit sniffing glue!”

The levity made things more bearable.

“Brian would just look at him and say, ‘Oh, no, here he comes again!’ ” said Smith’s mother, Virginia. “There was always a crowd in the room with Brian, and [Connor] . . . sort of worked the crowd. He was larger than life. He was such a good friend.”

Connor fretted when he left one bedside for another, or when he left everyone, just because he needed a break. He worried he did not visit his mother enough.

He was there just before Smith died, joining his mother and brother and father in telling him it was OK to let go, that Jesus was waiting. He coordinated every detail of Smith’s wakes and funeral, attended by more than 3,000 people. As Smith requested, he preached the homily at the Mass, which was said by Cardinal Sean P. O’Malley.

Embracing a new beginning

At Martin’s birthday Mass the same weekend, the homily was a conversation between Connor and the children; he sat down on the floor and spoke with them gathered around. Jane hopped over to Connor and sat beside him. On the way out, the little girl wheeled herself over to the priest, who pushed her out of the sanctuary as the congregation gave her a standing ovation.

Three days later, Connor went into surgery for the neck pain that had tormented him since his car was rear-ended last November. All spring, he suffered pain and numbness, and one hand was so weak he could not open a soda can without help. He emerged from surgery woozy and immobilized, but his brother and other close family and friends were there to care for him.

When he could finally focus, he said with a laugh, he found he could not bear to watch his favorite police shows. He tuned into HGTV.

More challenges lay ahead. His six-year term at St. Ann was slated to be up next year, and the archdiocese was beginning a massive reorganization. An opening had emerged at Sacred Heart in Weymouth, the parish where he had been a deacon, in the town where his mother now lived and not far from his brother’s family. The archdiocese’s personnel committee wanted him to go. He agreed it made sense.

That did not make it easier to leave a parish he loved, and had walked with through an inconceivable tragedy — or, for his parishioners, deeply scarred by the Marathon bombings, to say goodbye to him.

Bill Richard said the family has shared meals and sailing trips with Connor since returning home, and now “hope to spend time with him as much as a friend as a pastor.”

On a cool, sunny day last week, Connor stood outside Sacred Heart’s elementary school, welcoming children and parents on the first day of classes. A quartet of fourth-grade girls clammed up when he tried to coax them into conversation.

“It’s like, ‘I don’t know you,’ ” he said later in his office, with a rueful smile. “You’re the stranger. And this work is all about relationship.”

But a parish priest, he said, does not stay put. He serves the whole church, a few people at a time, following the example of Jesus, who went from village to village, preaching. Getting to know people takes time. And some of his new parishioners are not strangers — like Smith’s parents, and Marchese.

Sometimes, God had seemed absent in this devastating year, he would acknowledge that. But after a visit to Smith’s grave, just down the road from Sacred Heart, he said he felt no irony when considering his friend’s rhetorical question, posted on the grave marker.

On the wall of his new office is a photo of a candlelight vigil in Dorchester for Martin Richard, held the day after the bombings. It is early evening, but there is enough light “to scatter the darkness,” the priest said.

Correction: Because of a reporting error, an earlier version of this story about the Rev. Sean Connor misstated the position of the late Rev. Brian Smith of St. Mary’s Church in Foxborough. Smith was the parochial vicar of St. Mary’s.